API / $logger

Describes a logger instance. The message MUST be a string or object implementing __toString(). The message MAY contain placeholders in the form: {foo} where foo will be replaced by the context data in key "foo". The context array can contain arbitrary data. The only assumption that can be made by implementors is that if an Exception instance is given to produce a stack trace, it MUST be in a key named "exception". See https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-3-logger-interface.md for the full interface specification.

Name Description
emergency System is unusable.
alert Action must be taken immediately. Example: Entire website down, database unavailable, etc. This should trigger the SMS alerts and wake you up.
critical Critical conditions. Example: Application component unavailable, unexpected exception.
error Runtime errors that do not require immediate action but should typically be logged and monitored.
warning Exceptional occurrences that are not errors. Example: Use of deprecated APIs, poor use of an API, undesirable things that are not necessarily wrong.
notice Normal but significant events.
info Interesting events. Example: User logs in, SQL logs.
debug Detailed debug information.
log Logs with an arbitrary level.